Rev. Bras. Cir. Plást. 2011; 26(4): 555-60 555 Effects of hyperbaric oxygenation and N-acetylcysteine on the survival of random-pattern skin flaps in rats Effects of hyperbaric oxygenation and N-acetylcysteine on the survival of random-pattern skin flaps in rats Efeito da oxigenação hiperbárica e da N-acetilcisteína na viabilidade de retalhos cutâneos em ratos ABSTRACT Background: Advances in plastic surgery techniques have enabled reconstruction of extensive wound damage, especially through

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... use of random flaps. However, the limiting factor for the use of these flaps is the unpredictable blood supply, which may produce irreversible damage to the microcirculation and result in partial or complete flap necrosis, making the wound more susceptible to infection. Therefore, improvement of random flaps, especially in the distal extremity, has been an essential goal for the success of this technique. The objective of this study was to investigate the effects of hyperbaric oxygenation (HBO), N-acetylcysteine (NAC), and the combination of both (HBO + NAC) on the degree of necrosis in modified McFarlane random skin flaps on Wistar rats. Methods: A total of 32 male Wistar rats were randomly divided into a sham treatment group (SG, n = 8), N-acetylcysteine group (NACG, n = 8), hyperbaric oxygenation group (HBOG, n = 8), and hyperbaric oxygenation plus N-acetylcysteine group (HNG, n = 8). Modified McFarlane random flaps were created in the dorsal region of the rats. Results: The average area of the flaps exhibiting necrosis was 18.3%, 24.3%, 12.6%, and 14.9%, in the SG, NACG, HBOG, and HNG, respectively. The necrotic areas in the HBOG and HNG were significantly smaller than that in the NACG. Conclusions: HBO treatment was associated with a reduction in the area of necrosis in the skin flaps. NAC treatment alone gave poor results. The use of HBO and NAC in combination did not improve the outcome compared with the use of HBO alone. The findings suggest that oxygen diffusion through the interstitial space was the factor responsible for the favorable results of HBO. RESUMO Introdução: Os avanços das técnicas em cirurgia plástica permitiram a reconstrução de extensos defeitos causados por ferimentos, entre as quais destaca-se a utilização dos retalhos randômicos. No entanto, o fator limitante para a utilização desses retalhos é a imprevisibilidade de sua vascularização distal, o que poderá ocasionar danos irreversíveis à microcirculação, resultando em necrose parcial ou completa do retalho, tornando a ferida mais suscetível a infecção. Portanto, melhorar a viabilidade do retalho randômico, principalmente em sua extremidade distal, tem sido uma meta importante para o sucesso dessa técnica. O objetivo deste estudo foi investigar o papel da oxigenação hiperbárica (OHB), da N-acetilcisteína (NAC) e da associação de ambas (OHB + NAC) na área de necrose em retalhos randômicos modificados de McFarlane em pele de ratos Wistar. Método: No total, 32 ratos Wistar machos foram divididos aleatoriamente em grupo Sham (GS, n = 8), grupo N-acetilcisteína